Tool for lapping internal surfaces



Mayl 15, 1928.

C. P. GRIMES TOOL FOR LAPP'IING'INTERAL SURFACES Filed Feb. 2z,l 1927 A TTORNEY Patented May 15, 1928.

. l 1,670,068 ,rfarjsrrrv OFFICE.

l CHARLES I. GRIMES, OF SYBLAC'USE, NEW YORK.

TOOL F03 LAPPING INTERNAL SURFACES. v

pplicationrled February 23, 1927. Serial No. 170,349.

This invention has for its object a particularly simple, 'durable v,and eiiicient lapping ytool or tool designed to nish, smooth, polish or abrade internal cylindrical surfaces, as the interiors of cylinders. l `The tool is particularly designed for iinishlng or refinishing the cylinders used for operating hydraulic brakes on motor ve hicles without demounting the 'cylinders' from the chassis.

The invention consists in the novel features and in the combinations and constructions hereinafter set forth and claimed,

In describing this invention reference is had to the accompanying drawings in which like characters designate correspondingvparts in all the v iews.

Figure 1 is an elevation partly in section of a preferable embodiment of this tool.

Figure 2 is an' enlarged cross sectional view through the tool showing the same Within the cylinder.

Figure 3 is a fragmentary end elevation illustrating `the manner of securing the abrading strips in position.

This tool comprlses generallyia centrifugally operated abradingmember and means The abrading for rotating said member'. member has a flexible portion arranged to conform to an internal .cylindrical surface and to b e thrown outwardly by the centrifugal force against said surface. The abrading member is resilient or has a resilient` backing so that it tends to press'outwardly under theinfluence of its resiliency as well as throw outwardly.4 Preferably there are a plurality of abrading` members in order to balance theftool during the rotation thereof as well as more accurately center it in the internal cylindrical surface. The backings are usually mounted on 'a body member in.- stead of directly together and-the'body member dias a shank for connection to'any source of power. f

1 designates the bod'v which may be of any suitable'form, size and construction, it having a shank 2 connected thereto by a universal joint 3. The universal joint is stiffened somewhat by a 'resilient means tendy. ing to yieldingly oppose its angular movement, this means being here shown as a rubber sleeve 4 around the joint. This rubber ,sleeve acts to prevent the body from folding 'to a too great angle to the shank 2 in order that the tool can be .readily inserted 1n the" cylinder as 5. v l

The tool is here shown as provided with a pair ofoppositely disposed abrading members. each member being in the form of a exible leaf secured at one end lto the body,- land normally extending outwardly therefrom, and being wrappable around the body` to conform to the internal cylindrical sur-V faceso that the 7free end portion of each ,member trails during the rotation of th body, and is thrown outwardly against the lntcrnal cylindrical surface. Each abrading member as `here shown comprises a rubber backing leaf 6, the leaves being mounted on opposite sides of the body, and extending outwardly in opposite directions therefrom,

each leaf being wrapped around one side edge of the body, so that its end portion trails.- The abrading members in addition to the backing leaves 6 include abrading strips 7 overlying the backing leaves 6. I

' The body 1 is here shown as oblong in general form in cross section, and with ends beveled or rounding in opposite directions, an'd each backing leaf has its inner end por tion mounted upon one of the flat sides of the oblong formation, and is folded around one of the rounding ends.' That is it is so folded. when the tool is inserted in a cylinder. The backing leaves are secured to the base in any suitable manner as by screws 8. The abrading material is preferably applied to a detachable strip instead of to the backing, these abrading strips being in the nature of 4emery cloth or paper andare detachably secured in position in order that they may be readily removed and replaced.

vEach abrading strip 7 is preferably secured tothe side of the body opposite to that on which its companion backing strip is mounted. and underlies the .inner end `portion of the other backingstrlp, and as here illustrated the body is formed with pins 9 gardless ofl whether or not thel abrading strips have been previously formed with perforations. Normally the backing strips on account of 'being of rubber or some other resilient material extend outwardly in nearly astraight line. y

in operation thel strips are preliminarily rolled or wrapped into cylindrical form, and inserted into `the cylinder. The shank 2 of ethe tool is then connected to any suitable source of power so that the tool is rotated. During v the rotation, the backingl members press outwardly under their own c resiliency, andare-also thrown outwardly by the centrifugal force, and 'owing to the universal joint 3, these bacliing strips or the tool centers itself in the cylinder.-

Ihis tool is particularly advantageous, in that it centers itself and bears substantially-equally throughout a circle of the internal surface, and further in that it is particularly economical to manufacture and is readily handled or inserted and removed.

What I claim is:

1. A tool of the character described comprising a rotating body oblong in general form and cross section, a backing of iiexble .resilient material in the form of a leaf lapping one of the long sides of the oblong body formation,and wrappable around one.

end of the oblong formation into position to conform to an internal cylindrical surface,

the free end portion nbeing spaced apart from the body and abrading means fon the outer side of the backing.

2. A tool-of the character described comprising a rotating body oblong in general form and cross section,a backing offiexble resilient material in the form of a leaf i ap 3. A tool of theAcharacter described comprising a rotating body'. oblong in general form and cross section, a backing of flexible Y resilient material in the form of a leaf lapping and secured to oneofthe long sides of the oblong body formation, and wrappable.

around one` end of thefoblong formation intopositionto conform to an internal cylindrical surface, the, free end portion being spaced apart from the/body and an abrading stri positeslde ofthe .-oblono body formation to that on which the-bac 'ng is located, the abrading strip tbeingwrappedY around the outer surface pf. the backing, and a pin pro` Jectlng from the'bod'y through the inner end of the strip. v Y

4. A tool of the character described comprism'g a rotating body, a pair ,of resilient j backin 'psin the form of leaves hayin .like endsSign g mounted: on the .body on oppositel having one end secured 'to' the op` sides of its axis, and. wrappable in opposite directions around the body to conform to .an yinterior cylindricalsurface, abrading strips wrapped around ythe outer surface of each of thebacking strips, the inner end of each abrading strip overlying the opposite side of the body to that-on which its companion" backing strip is mounted and k underlying the inner end portion of the other backing strip. f

5.\A tool of the character described 'comprising a rotating body, a pair of resilient baiingstripsin the form of leaves having like ends mounted on the body on 'opposite i sides of its axis, and -Wrappable in opposite directions around the body to. conform to au interior cyllndrical surface, an abradin strip Iwrapped around the outer surface o cach of the backing strips, the inner end of i each .abradiu stri overl the op osite side of the bddy td) that -oslrimvghich thepcompanion backing strip is mounted and underlying the inner end .portionl of the other backing strip, and the body being formed with pins projecting therefrom on which' the inner ends of the leaves are impaled, andthe backing strips being formed with'openings for recelving the pms.

6. A tool of the character described com-f prising a rotating body, backing strips of ex'ible resilient material in the form of leaves having their inner end portions se-VA cured to the body, the strips extendngin opposite directions and wrappable in op o site directions into the general form ofJ a letter S whereby the outer free portions of the backing strips conform to an internal cylindrical surface, abradng stri s overlying each backing leaf, each Strip h 4end portion overlying the opposite sideof the body to that on which its companion" backing lleaf is mounted, and underlymgthe inner end portion of the other leaf.

7. A tool of the character described comprising a rotating body oblong ingeneral aving lts form in -cross section, backin strips.A of

flexible resilient material-'in t e form of leaves 'having their inner end rtions secured to the long sides of the ob ong forma'- tion, the strips extending in opposite directions and wrappable in opposite' directions around the end of the oblong formation into.v the general form'of a letter S whereby. the

outer free portions of the backing strips conform to'an internal cylindrical surface,

abrading strips overlying each backing leaf, ,each strip having-'its end portions' overlying the opposite side of theoblong :forma-v tion to that on whichits companion' backing leaf 1s mounted and underl 'v the inner VVINI end portion of the 'other lea and the j being formed-with pins projecting from 'op` posite sides thereof, and the'backing' leaves pns,'tl 1e inner' end 'portionof each/backing being impaled on their'4 inner endsjonvthe leaf having openings for receiving the pins.

8. A tool of the character described comprising a rotating body and a centrifugally operated member comprising backing leaves of flexible material, 'each secured at one end to the body and the inner end portion thereof lapping the body, abrading means on the outer side of eachleaf in the form of a strip overlying each backing leaf and extending at its inner end between the body and the inner end portion of the other backing leaf.

9. A tool of the character described comprising a rotating body and a centrifugal- 1y operated member comprising backing leaves of flexible material, each Asecured at one end to the body and the inner end portion lapping the body, abrading. means onv the outer side of each leaf in the form of a. strip voverlying each backing leaf 4and extending at its inner. end between the body and-the inner end portion of the other backing leaf and pins in the body having points extending through the .abrading strips, thebacking leaves having perforations for receiving the points of the pins extending through the abrading strips associated with` the other leaf.

In testimony whereof, I have hereunto signed my name at Syracuse, in the county of Onondaga, and State of New York, this 12th'day of February, 1927.

CHARLES P. GRIMES. 

